Meanwhile, the Nittany Lions are ineligible to play in a bowl game or win the Big Ten until 2016.
"Sanctionwise, certainly we lost some kids because of sanctions. I mean, there's no question about it," O'Brien said. "I'm not going to sit up here and tell you that the sanctions didn't play a factor in some of the guys we set out to recruit."
O'Brien mentioned the importance of Penn State's walk-on program (he terms it "run-on") in light of the scholarship limits. That, along with the continued commitment of recruits who pledged to the university before the sanctions, were reasons why O'Brien called Wednesday a "great day for Penn State."
"It's almost impossible to say this, to do this, but you really can't miss when you can only sign 15 scholarship players," O'Brien said. "We feel really good about where we're at, but only time will tell."
To be successful, O'Brien said he'll have to be as thorough as can be with recruiting, but later said the program would never join the ranks of the "Wild, Wild West"; that is, he'll obey all of the NCAA's recruiting rules. He also said the type of high-character players he wants won't change.
In terms of the run-ons, O'Brien said about 15 to 20 of them will be there when training camp begins.
"We're not about collecting talent," O'Brien said. "We're about building a team."
The signal caller
Five-star recruit Christian Hackenberg has a lot of studying to do to learn how to play quarterback at the college level, O'Brien said.
But that doesn't mean he isn't out of the equation for a starting role.
"Christian, Steven Bench, Tyler Ferguson - any one of those guys could be our starting quarterback against [2013 season opener] Syracuse, no question about it," O'Brien said.
Bench is a rising sophomore who saw very limited action last season. Ferguson is a junior college commit from College of the Sequoias in Visalia, Calif.
O'Brien said he might not name a starting quarterback at the end of spring practice.
Redshirting players could limit what Penn State could do with scholarships even more, and O'Brien said those decisions will require careful evaluation.
"If these guys are ready to play, then, as a coaching staff, we make the decision to let them play. We involve their parents in that decision," O'Brien said. "And then when we play them, we have to play them."
In non-recruiting news, Penn State announced that it will play Central Florida in Beaver Stadium on Sept. 14, replacing Virginia. The Cavaliers left the 2013 schedule to play an additional home game.
O'Brien coached with UCF coach George O'Leary from 1995-2001 at Georgia Tech. The Knights are coming off a 10-4 season (7-1 in Conference USA) that culminated with a win in the Beef 'O' Brady's bowl over Ball State.